Water-cooled reactor core test apparatus

ABSTRACT

An apparatus for testing a water-cooled reactor core in which the reactor core to be tested is placed in a casing within a pressure chamber which has an internal diameter slightly larger than the external diameter of the reactor core casing such that an annular flow passage is created between them. An impeller type pump mounted on top of the pressure chamber has its inlet port connected to one end of the reactor core casing. The pump circulates demineralized water up through the reactor core and the casing and discharges fluid into the annular flow passage to reenter the opposite end of the reactor core casing. Heaters mounted on the outside of the pressure chamber control the temperature of the fluid within the pressure chamber. An external pump initially fills the chamber and thereafter maintains the fluid within the pressure chamber at predetermined pressure.

United States Patent 1 Bowles 1 Nov. 20, 1973 Arnold Gordon Bowles, Warren, Pa.

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11.8. CI. 73/432 SD, 73/37, 73/86 Int. Cl. G0lm 19/00 Field of Search 73/37, 86, 168, 432 SD 3,102,415 9/1963 Hanggi et al 73/37 3,504,323 3/1970 Meany, Jr. 73/86 FOREIGN PATENTS OR APPLICATIONS 120,945 10/1958 U.S.S.R 73/86 Primary ExaminerS. Clement Swisher Attorney-Charles B. Smith [57] ABSTRACT I An apparatus for testing a water-cooled reactor core in which the reactor core to be tested is placed in a casing within a pressure chamber which has an internal diameter slightly larger than the external diameter of the reactor core casing such that an annular flow passage is created between them. An impeller type pump mounted on top of the pressure chamber has its inlet port connected to one end of the reactor core casing. The pump circulates demineralized water up through the reactor core and the casing and discharges fluid into the annular flow passage to reenter the opposite end of the reactor core casing. Heaters mounted on the outside of the pressure chamber control the temperature of the fluid within the pressure chamber. An external pump initially fills the chamber and thereafter maintains the fluid within the pressure chamber at predetermined pressure.

3 Claims, 2 Drawing Figures 1 WATER-COOLED REACTOR CORE TEST APPARATUS BACKGROUND OF THE INVENTION The invention relates to test systems for water-cooled reactor cores. Such testing of water-cooled reactor core assemblies requires simulation of the actual conditions of temperature and flow under which such cores are operated throughout a long period of time in order to prove the mechanical integrity of the core. Many prior test systems commonly employ an annularly shaped test loop. The test assembly is mountedin one leg of the test loop and a circulating pump is mounted in another leg of the test loop. The fluid is circulated throughout the entire loop.

Such annular loop installations are generally quite large. Most of the materials employed, because of the temperatures and pressures involved, are expensive, high alloy steels. The shape of such systems produces a waste of materials since the exterior surface of the loop assembly is only exposed to the atmosphere and thus does not need to be made of such high quality materials. It also must be thick walled to withstand the pressure differential between the atmosphere and the interior of the loop assembly.

SUMMARY OF THE INVENTION A preferred embodiment of the present invention comprises a hollow pressure chamber in which the test core is mounted in an open ended casing. The external diameter of the core casing is substantially smaller than the internal diameter of the pressure chamber so that an annular fluid passage which extends over the length of the core casing is created between them. A circulating pump is mounted at the top of the pressure chamber and means are provided for a fluid connection between the inlet of the pump and one open end of the core casing. The outlet of the pump discharges fluid into the annular fluid passage. The other open end of the core casing is in fluid communication with the annular fluid passage.

The pump draws fluid up through the test core in the pressure chamber and returns the fluid to the bottom of the test core through the annular fluid passage created between the exterior surface of the core casing and the interior surface of the pressure chamber. Strip heaters mounted on the exterior of the pressure chamber control the temperature of the fluid within the pressure chamber. Because the surfaces of the pressure chamber and the core casing act as the walls of the return leg of the test loop a saving in space and materials is effected. Substantially all the surfaces of the high alloy steel reactor core casing are exposed to the test environment. Furthermore since the core casing is exposed to only a small pressure differential it does not need to be thick walled.

Still another advantage is that the whole test system is more simply constructed and may be assembled with fewer pieces to join together than in prior loop systems.

It is therefore an object of the present invention to provide a water-cooled reactor test system of relatively small size and simple construction which minimizes the quantity of materials required.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical view, in section, of one embodiment of the invention;

DESCRIPTION 0E C RTAIN PREFERRED EMBODIMENTS Referring now more particularly to FIG. 1 there is I shown a pressure chamber generally designated as 10 mounted on an upright frame 12. The pressure chamber includes an upper section 14 containing a pump 16 of the impeller type and a lower section 18 in which a reactor test core housing 20 is mounted. Sections 14 and 18 are joined through a flange 22 of the housing which has a plurality of perforations 24 in its surface to provide fluid communication between the two sections. The flange 22 also has a rectangular hole 26 through its center which matches the rectangular cross-section of the reactor test core.

The pump 16 has an intake 28 which is coupled to the hole 26 by a hollow cylinder 27. The pump draws fluid up through the test core and the rectangular hole 26 in the flange 22. The external diameters of the pump 16 and cylinder 27 are less than the internal diameter of the chamber section 14 so that an annular fluid passageway 54 is created between them. The pump has a perforated outlet port 30 which discharges fluid into the passageway 54 to circulate downwardly from chamber section 14 to chamber section 18 through the perforations 24 in the flange 22 as indicated by the flow lines shown in FIG. 1. A port 31 in the upper section 14 and a port 32 in the lower section 18, disposed on opposite sides of the flange 22, are connected to a pressure differential measuring device 33 which allows the flow rate through the perforations 24 in the flange to be calculated.

A plurality of strip electrical heaters 35 are fastened to the exterior of the upper section 14 to heat the upper pressure chamber and thereby control the temperature of the fluid within the pressure vessel. An insulating cover 34 encases the entire pressure vessel, with the exception of its upper and lower ends, to maintain the temperature of the fluid substantially constant and prevent heat loss.

The pump 16 is driven by a motor 36 mounted on a projecting leg 38 of the frame 12. The motor 36 may be either electrical or hydraulic and is illustrated in FIG. 1 as being hydraulic and powered by an electric pumping assembly 51. The torque of the motor is carried by a shaft 40 to a right angle drive 42 mounted on the top of the pressure chamber 10.

The output of the right angle drive 42 is connected by a shaft 44 to the pump 16 through a pressure closure 46 mounted on top of the upper end of section 14. Various seals are mounted about the shaft 44, but are not shown in detail since they are well known in the art, to prevent the escape of fluid through the shaft housing. A pair of sampling pipes 48 and 50 are provided in the pressure chamber to allow checking of the water purity.

The reactor test core is contained in a casing 52 mounted along the vertical axis of the lower section 18 of the pressure chamber 10. The outer diameter of the casing 52 is substantially less than the internal diameter of the lower section 18 of the pressure chamber, thereby creating an annular fluid passage 55 between the perforated flange 22 and the bottom of the casing 52. At the bottom of the casing 52 are a plurality of inlet ports 56 which allow fluid within the pressure chamber to enter the interior of the casing 52 from the passage 55 and to pass through the reactor test core.

The pump 16 circulates fluid from its outlet down through passage 54 in the upper chamber section 14, through the perforations 24 of the flange 22, through the passage 55 in the lower chamber section 18, into the openings 56 in the bottom part of the casing 52, up through the reactor test core, the rectangular aperture 26 in the flange 22, and the cylinder 27 to return to the inlet port 28 of the pump 16. By having the exteriors of the casing 52, the cylinder 27 and the pump 16 act as one wall of the return passage for the fluid a saving in space and material is effected. Since the casing 52 is subjected to only a small differential pressure, it need not be thick and thus a saving in high alloy material is effected.

The bottom of the lower chamber section 18 is closed by a plug 60 held in place by an annular member 62 threadably engaged with the lower opening in the chamber section 18. A penetration 64 through the plug 60 allows access to the interior of the lower chamber section 18 for monitoring purposes. The pressure chamber is filled with fluid and maintained at a predetermined pressure through a second penetration 66 in the plug 60 to which a line 68 is connected from a high pressure fluid pump 70. The reactor core may be inserted and removed through the bottom of chamber section 18 by removing the plug 60.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

l. A system for testing a water-cooled reactor core comprising a closed, hollow pressure chamber, an open ended casing for holding the test core, the casing being mounted in the pressure chamber and having an external diameter which is substantially less than the internal diameter of the pressure chamber so as to create a first fluid passage therebetween, a fluid pump having an inlet and an outlet port, the outlet port being in fluid communication with the first fluid passage, means connecting the inlet port of the pump to one end of the core casing, means for providing fluid communication between the other end of the core casing and the first fluid passage.

2. A reactor core testing system as recited in claim 1 further comprising heating elements mounted on the pressure chamber for controlling the temperature of the fluid within the pressure chamber.

3. A reactor core testing system as recited in claim 1 comprising a pressure chamber having an upper and a lower section, the core casing being contained within the lower section and the pump being contained within the upper section, the external diameter of the pump being substantially less than the internal diameter of the upper section so as to create a second fluid passage therebetween, the core casing having a perforated flange which joins the upper and lower chamber sections, the first and second fluid passages being in fluid communication through the perforated flange, and the outlet of the pump being in direct fluid communication with the second fluid passage. 

1. A system for testing a water-cooled reactor core comprising a closed, hollow pressure chamber, an open ended casing for holding the test core, the casing being mounted in the pressure chamber and having an external diameter which is substantially less than the internal diameter of the pressure chamber so as to create a first fluid passage therebetween, a fluid pump having an inlet and an outlet port, the outlet port being in fluid communication with the first fluid passage, means connecting the inlet port of the pump to one end of the core casing, means for providing fluid communication between the other end of the core casing and the first fluid passage.
 2. A reactor core testing system as recited in claim 1 further comprising heating elements mounted on the pressure chamber for controlling the temperature of the fluid within the pressure chamber.
 3. A reactor core testing system as recited in claim 1 comprising a pressure chamber having an upper and a lower section, the core casing being contained within the lower section and the pump being contained within the upper section, the external diameter of the pump being substantially less than the internal diameter of the upper section so as to create a second fluid passage therebetween, the core casing having a perforated flange which joins the upper and lower chamber sections, the first and second fluid passages being in fluid communication through the perforated flange, and the outlet of the pump being in direct fluid communication with the second fluid passage. 